CN105273638A - Anti-cleavage suspended grinding fluid for gallium oxide wafer and preparation method thereof - Google Patents

Abstract

The invention discloses an anti-cleavage suspended grinding fluid for a gallium oxide wafer and a preparation method thereof. The fluid is prepared from aluminium oxide micropowder, a dispersing thixotropic agent, a surfactant, kerosene, an alkane, a pH value conditioning agent, an antifoaming agent, a bactericide and a cleaning auxiliary agent. The anti-cleavage suspended grinding fluid is preferably obtained through a large amount of experiments. The grinding fluid is good in stability, and is applicable to rough grinding and smooth grinding of the gallium oxide wafer. The material removal speed is fast, and the wafer surface is smooth and does not have obvious scratches or pits. The grinding fluid is capable of reducing mechanics expansion effect during grinding on surface micro cracks, stress damage layers and other defects left after cutting is performed , is capable of effectively inhibiting cleavage defects during grinding of the gallium oxide wafer, also is low in cost and beneficial for popularization application, and overcomes many disadvantages in the prior art.

Description

Gallium oxide wafer anti-cleavage suspension slurry and preparation method thereof

technical field

The invention relates to the technical field of grinding processing of gallium oxide wafers (β-Ga ₂ O ₃ ), in particular to an anti-cleavage suspension polishing liquid suitable for high-efficiency and high-quality rough/finish grinding of gallium oxide wafers and a preparation method thereof.

Background technique

Gallium oxide (β-Ga ₂ O ₃ ), as a new gallium nitride (GaN) substrate material, has a higher lattice mismatch rate than traditional sapphire (Al ₂ O ₃ ), silicon carbide (SiC) and other materials. Low, forbidden band width of 4.8 ~ 4.9eV, visible light band transmittance greater than 80%, the shortest transmittance wavelength of 260nm and other excellent photoelectric properties. The light transmittance of this material is comparable to that of Al ₂ O ₃ , the electrical conductivity is quite similar to that of SiC, and it can grow large-size single crystals through the melt method. It is an ideal GaN substrate to replace Al ₂ O ₃ and SiC material, therefore, it has a very broad market prospect in the field of optoelectronic devices.

With the development of high-brightness and high-efficiency LED technology, the ultra-precision processing technology of the substrate wafer surface is facing more stringent requirements. On the basis of ensuring the high integrity of the wafer surface, the requirement for surface roughness has reached the sub-nanometer level. Rough/finish grinding is designed to remove saw marks, microcracks and sub-surface damage layers generated when dicing wafers, and is a key process step before obtaining ultra-smooth and damage-free surfaces through chemical mechanical polishing (CMP). Gallium oxide (β-Ga ₂ O ₃ ) crystal material has the hard and brittle characteristics of traditional optoelectronic materials such as Al ₂ O ₃ and SiC. , The grinding pressure is relatively high, and it is easy to produce scratches, pitting and other defects on the wafer surface. In addition, the material also has unique characteristics of easy cleavage, with 100 cleavage surfaces, which are extremely sensitive to the grinding pressure, internal stress, and process temperature during rough/finish grinding, and are especially prone to defects such as cleavage cracks. This further affects the overall efficiency and quality of the subsequent polishing process of the gallium oxide wafer.

At present, the polishing liquid suitable for Al ₂ O ₃ , SiC and other crystal material wafers does not consider the physical and chemical characteristics of the gallium oxide material itself in the selection of abrasives and the proportion of the polishing liquid. During rough/fine grinding, it is difficult to obtain high-quality wafers with high wafer surface integrity and low wafer surface damage layer, which seriously affects the subsequent processing quality of wafers. Therefore, it is particularly urgent to study the rough/finish grinding process of gallium oxide wafers, especially the special anti-cleavage suspension slurry.

Contents of the invention

Purpose of the invention: The present invention is aimed at the problems of low rough/finish grinding processing efficiency of gallium oxide wafers, low wafer surface quality, and easy occurrence of cleavage cracks and scratches in the prior art. Gallium wafer anti-cleavage suspension slurry and preparation method thereof. The suspension state of the grinding liquid provided by the present invention is relatively stable, and there is no obvious component substance precipitation after a long period of time, and the grinding particles are evenly dispersed. Using the grinding liquid to perform rough/finish grinding on the wafer, the material removal rate is fast, and the surface can be obtained. High-quality wafers with high integrity and low surface damage layer can overcome the deficiencies of the prior art.

Technical scheme: in order to realize above object, the main technical scheme that the present invention adopts is:

A gallium oxide wafer anti-cleavage suspension slurry, which is made of the following raw materials in weight percent:

Aluminum oxide powder 1-10%, dispersing thixotropic agent 1-5%, surfactant 1-10%, kerosene 40-50%, alkane 20-30%, pH regulator 1-3%, defoamer 0.01 ～0.03%, fungicide 0.01～0.02%, cleaning agent 0.01～0.1%.

As a preferred version, the gallium oxide wafer anti-cleavage suspension slurry described above is made of the following raw materials in weight percentage:

Aluminum oxide powder 5-10%, dispersing thixotropic agent 3-5%, surfactant 5-10%, kerosene 45-50%, alkane 25-30%, pH regulator 1-3%, defoamer 0.02 %, fungicide 0.02%, cleaning agent 0.05%.

As a preferred solution, in the anti-cleavage suspension grinding liquid for gallium oxide wafers mentioned above, the alumina micropowder is α-Al ₂ O ₃ , the purity is above 99.9%, and the particle size of the micropowder is 0.5-15 μm. Micropowder abrasives with a larger diameter of 5-15μm, optional models: W7, W10, W14. For fine grinding, use micropowder abrasives with a smaller particle size of 0.5-5 μm, optional models: W0.5, W1, W1.5, W2.5, W3.5.

As a preferred version, in the anti-cleavage suspension slurry for gallium oxide wafers described above, the dispersing thixotropic agent is one or more mixtures of polyvinyl alcohol and cellulose derivatives, and when several kinds are mixed, each group The configuration ratio between parts is equal parts or other ratios, wherein the cellulose derivatives are mainly hydroxyethyl cellulose, cyanoethyl cellulose and ethyl cellulose.

As a preferred version, in the anti-cleavage suspension polishing liquid for gallium oxide wafers described above, the surfactants are octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ether, and fatty acid polyoxyethylene ether. One or more mixtures of oxyethylene ether, polyoxyethylene sorbitan monooleate and methyl stearate polyoxyethylene ether. Octylphenol polyoxyethylene ether and nonylphenol polyoxyethylene ether are preferred, and when multiple types are mixed, the configuration ratio of each component is equal parts or other ratios. The surfactants are all polyoxyethylene type nonionic surfactants, thereby reducing the secondary pollution caused by foreign metal ions to the grinding wafer.

As a preferred version, in the anti-cleavage suspension grinding fluid for gallium oxide wafers described above, the kerosene is a mixture of alkanes, aromatic hydrocarbons, cyclic hydrocarbons and unsaturated hydrocarbons, and the alkane is a straight line containing 11 to 13 carbon atoms. chain liquid alkanes.

As a preferred version, the above-mentioned gallium oxide wafer anti-cleavage suspension grinding liquid, the pH regulator is divided into two kinds of alkaline and acidic, wherein the alkaline regulator is an organic base pH regulator, composed of ethanolamine, A mixture of any one or more of ethylenediamine, triethylamine, and triethanolamine. When multiple mixtures are mixed, the configuration ratio between the components is equal or other ratios, and the organic base does not contain metal ions; wherein The acid regulator is one or a mixture of hydrochloric acid or phosphoric acid, and when the two are mixed, the configuration ratio of each component is equal parts or other ratios.

As a preferred version, the above-mentioned gallium oxide wafer anti-cleavage suspension grinding liquid, described defoamer is polydimethylsiloxane, polyoxyethylene polyoxypropylene pentaerythritol ether and polyoxyethylene polyoxypropanolamine Any one of ethers; the bactericide is any one of isothiazolinone and benzisothiazolinone; the cleaning aid is isopropyl ketone.

The preparation method of gallium oxide wafer anti-cleavage suspension abrasive liquid of the present invention, comprises the following steps:

(1) Mix kerosene and alkanes according to weight percentage, fully stir and fuse to obtain grinding liquid base liquid, let stand, cool to room temperature, and set aside;

(2) Under the condition of stirring, add alumina micropowder, dispersing thixotropic agent and surfactant to the base liquid obtained in step (1) according to the weight percentage, stir well, and then use ultrasonic dispersion to obtain the middle of the grinding liquid liquid, let stand, cool to room temperature, and set aside;

(3) Add defoamer, bactericide and cleaning aid to the intermediate liquid obtained in step (2) according to the weight percentage, stir well to obtain quasi-grinding liquid, let stand, cool to room temperature, and set aside;

(4) Measure the pH value of the quasi-grinding liquid obtained in step (3), add an appropriate amount of acidic or alkaline pH adjuster by weight as needed, slowly add it dropwise to the quasi-grinding liquid under stirring conditions, and adjust the grinding liquid The pH value is within the range of 8.0 to 9.0, and after being fully stirred and mixed uniformly, a gallium oxide wafer anti-cleavage suspension polishing liquid is obtained.

In the above-mentioned preparation method of gallium oxide wafer anti-cleavage suspension grinding liquid, the alumina micropowder is α-Al ₂ O ₃ , and the particle size of the micropowder is 0.5-15 μm;

The dispersed thixotropic agent is one or more mixtures of polyvinyl alcohol and cellulose derivatives, wherein the cellulose derivatives are mainly hydroxyethyl cellulose, cyanoethyl cellulose and ethyl cellulose.

In the above-mentioned preparation method of gallium oxide wafer anti-cleavage suspension slurry, the stirring is fully stirred by an electric magnetic stirring device.

The aluminum oxide grinding micropowder in the anti-cleavage suspension grinding liquid provided by the present invention mainly realizes the removal of larger cutting line marks, microcracks and damaged layers on the surface of gallium oxide wafers through mechanical friction. The grinding liquid is divided into coarse grinding liquid with larger grinding particles and fine grinding liquid with smaller grinding particles. It is used for rough/finish grinding of gallium oxide wafers, which can effectively avoid serious scratches, pitting and other defects on the wafer surface. . In addition, the polishing liquid can also reduce the mechanical expansion of defects such as surface microcracks and stress damage layers remaining after cutting during the polishing process, and effectively inhibit the generation of cleavage defects during the gallium oxide wafer polishing process. The present invention does not use the traditional diamond grinding abrasive with high price, but selects the alumina grinding abrasive with low price according to the characteristics of the gallium oxide material, which can effectively reduce the cost of the grinding liquid, and is easier to promote in industry. The alkaline pH adjuster selected by the anti-cleavage suspension grinding liquid provided by the present invention is organic alkali ethanolamine, ethylenediamine, triethylamine and triethanolamine, which can avoid the secondary pollution brought by foreign metal ions and reduce the impact on the grinding liquid. The pH value plays a role in maintaining stability. The dispersed thixotropic agent and nonionic surfactant screened by a large number of tests in the present invention can maintain the high stability of the abrasive micropowder in the grinding liquid, and can realize the suspension characteristics of the grinding liquid for a long time, thereby realizing stable and efficient coarse/finish Grinding process ensures high-quality gallium oxide wafer surface quality. The present invention adds an appropriate amount of polyoxyethylene type surfactant to realize low-foaming or even no-foaming of the anti-cleavage grinding liquid. The existence of organic components in the grinding liquid can easily lead to the generation of mold and deteriorate the grinding liquid. The fungicide can effectively inhibit the growth of mold, thereby solving the problem of long-term storage of the grinding liquid. The cleaning aid can effectively reduce particle adsorption and reduce the cost of subsequent cleaning of gallium oxide wafers.

Beneficial effect: compared with the prior art, the present invention has the following advantages:

1. The grinding liquid involved in the present invention is divided into the larger rough grinding liquid of grinding particles and the smaller fine grinding liquid of grinding particles, which are respectively used for the rough/fine grinding processing of gallium oxide wafers, the material removal rate is fast, and the wafer surface is relatively Smooth, without obvious scratches and pits, which can reduce the mechanical expansion of defects such as surface microcracks and stress damage layers remaining after cutting during the grinding process, and effectively inhibit the generation of cleavage defects during the grinding process of gallium oxide wafers.

2. The grinding liquid involved in the present invention is weakly alkaline, non-corrosive to the grinding equipment, easy to clean after the grinding process, and can avoid many disadvantages such as environmental pollution caused by the grinding liquid.

3. After being left for a long time, the grinding liquid involved in the present invention has excellent dispersion uniformity and stable suspension characteristics, which is convenient for transportation and storage, and the selection of low-cost alumina grinding abrasives can effectively reduce the cost of coarse/finish grinding.

4. After the gallium oxide wafer is ground with the suspended abrasive liquid prepared by the method of the present invention, the wafer has good flatness, and a ground surface with a low damage layer can be obtained. The removal rate of coarse abrasive material is 4.8 μm/min, and the value of surface roughness Ra is It reaches 2.1μm, the fine grinding material removal rate is 1.1μm/min, and the surface roughness Ra value can reach 140nm.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention, should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention, after having read the present invention, those skilled in the art will understand various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

Embodiment 1 The preparation method of gallium oxide wafer anti-cleavage suspension slurry comprises the following steps:

(1) Mix 2450g of kerosene and 1400g of alkane, and use an electric magnetic stirring device to fully stir and fuse for 15 minutes to obtain a grinding liquid base liquid, which is left to stand and cooled to room temperature for later use;

(2) Under the condition of stirring by electric magnetic stirring device, add 450g of alumina micropowder of W7 type, 200g of polyvinyl alcohol, and 400g of octylphenol polyoxyethylene ether into the base liquid obtained in step (1), and fully stir for about 15 minutes, then use ultrasonic dispersion, ultrasonic dispersion is 500W, and the dispersion time is 15 minutes, to obtain the intermediate liquid of the grinding liquid, stand still, cool to room temperature, and set aside;

(3) Add 1g of polydimethylsiloxane, 1g of isothiolinone, and 2.5g of isopropyl ketone to the intermediate liquid obtained in step (2), and stir thoroughly for 15 minutes to obtain a quasi-grinding liquid, which is left to stand and cooled to room temperature ,spare;

(4) Measure the pH value of the quasi-grinding liquid obtained in (3), and slowly add acid and alkali pH value regulators to the quasi-grinding liquid under stirring conditions as needed, and adjust the pH value of the grinding liquid to weak alkaline , within the required range of 8.0 to 9.0, wherein the acidic pH adjuster is hydrochloric acid, and the alkaline pH adjuster is ethanolamine. After fully stirring and mixing uniformly, the anti-cleavage suspension grinding for rough grinding of gallium oxide wafers is obtained. Liquid about 5000g.

Take the above-mentioned anti-cleavage suspension abrasive liquid for gallium oxide wafers for rough grinding experiments, and use Unipol-1502 automatic precision grinding and polishing machine to rough grind gallium oxide wafers. The overall size of the wafer is 15×15mm, and the grinding pressure is 400g/cm ² , the rotational speed of the grinding disc is 60RPM, and the flow rate of the grinding liquid is 30ml/min. After the rough grinding process, the surface integrity of the gallium oxide wafer is good, and there are slight scratches under the light observation. The value of the surface roughness Ra in the 25×25 μm plane area is 2.1 μm by using the VK-X100/X200 shape measurement laser microscope. Sartorisu CP 225D precision electronic balance (accuracy 0.01mg), weighed the gallium oxide wafer before and after rough grinding, and calculated the grinding material removal rate of the grinding liquid to be 4.8 μm/min. It can be seen that the polishing solution in Example 1 of the present invention is suitable for rough polishing of gallium oxide wafers.

Embodiment 2 The preparation method of gallium oxide wafer anti-cleavage suspension slurry comprises the following steps:

(1) Mix 2280g of kerosene and 1500g of alkane, and use an electric magnetic stirring device to fully stir and fuse for 15 minutes to obtain a grinding liquid base liquid, which is left to stand and cooled to room temperature for later use;

(2) Under the condition of stirring with an electric magnetic stirring device, add 480g of alumina micropowder of W10 type, 110g of polyvinyl alcohol, 110g of cyanoethyl cellulose, and 420g of nonylphenol polyoxyethylene ether to the product obtained in step (1). In the base liquid, fully stir for about 15 minutes, and then use ultrasonic dispersion, the ultrasonic dispersion is 500W, and the dispersion time is 15 minutes, to obtain the grinding liquid intermediate liquid, stand still, cool to room temperature, and set aside;

(3) Add 1 g of polyoxyethylene polyoxypropylene pentaerythritol ether, 1 g of benzisothiazolinone, and 2.5 g of isopropyl ketone into the intermediate liquid obtained in step (2), and stir thoroughly for 15 minutes to obtain a quasi-grinding liquid. Cool to room temperature and set aside;

(4) Measure the pH value of the quasi-grinding liquid obtained in (3), and slowly add acid and alkali pH value regulators to the quasi-grinding liquid under stirring conditions as needed, and adjust the pH value of the grinding liquid to weak alkaline , within the required range of 8.0 to 9.0, wherein the acidic pH adjuster is phosphoric acid, and the alkaline pH adjuster is ethylenediamine. After fully stirring and mixing uniformly, the anti-cracking agent used for rough grinding of gallium oxide wafers is obtained. Suspend grinding liquid about 5000g.

Take the above-mentioned anti-cleavage suspension abrasive liquid for gallium oxide wafers for rough grinding experiments, and use Unipol-1502 automatic precision grinding and polishing machine to rough grind gallium oxide wafers. The overall size of the wafer is 15×15mm, and the grinding pressure is 420g/cm ² , the rotational speed of the grinding disc is 60RPM, and the flow rate of the grinding liquid is 35ml/min. After the rough grinding process, the surface integrity of the gallium oxide wafer is good, and there are slight scratches under the light observation. The value of the surface roughness Ra in the 25×25 μm plane area is 2.8 μm using the VK-X100/X200 shape measurement laser microscope. Sartorisu CP 225D precision electronic balance (accuracy 0.01mg), weighed the gallium oxide wafer before and after rough grinding, and calculated the grinding material removal rate of the grinding liquid to be 5.2 μm/min. It can be seen that the polishing solution in Example 2 of the present invention is also suitable for rough polishing of gallium oxide wafers.

Embodiment 3 The preparation method of gallium oxide wafer anti-cleavage suspension slurry comprises the following steps:

(1) Mix 1000g of kerosene and 590g of alkane, and use an electric magnetic stirring device to fully stir and fuse for 15 minutes to obtain a grinding liquid base liquid, which is left to stand and cooled to room temperature for later use;

(2) Under the condition of stirring by electric magnetic stirring device, add 100g of alumina micropowder of W0.5 type, 80g of hydroxyethyl cellulose, and 180g of nonylphenol polyoxyethylene ether into the base liquid obtained in step (1) , fully stirred for about 20 minutes, and then used ultrasonic dispersion. The ultrasonic dispersion was 500W, and the dispersion time was 25 minutes.

(3) Add 0.4g of polyoxyethylene polyoxypropanolamine ether, 0.4g of benzisothiazolinone, and 1g of isopropyl ketone to the intermediate liquid obtained in step (2), and stir thoroughly for 20 minutes to obtain a quasi-grinding liquid. Place, cool to room temperature, and set aside;

(4) Measure the pH value of the quasi-grinding liquid obtained in (3), and slowly add the acid and alkali pH value regulators into the quasi-grinding liquid under the condition of stirring according to the need, wherein the acidic pH value regulators are phosphoric acid, alkali The pH adjuster is triethylamine, adjust the pH value of the grinding liquid to weak alkaline, within the required range of 8.0 to 9.0, after fully stirring and mixing, the anti-cleavage agent used for rough grinding of gallium oxide wafers can be obtained. Suspend grinding liquid about 2000g.

Take the above-mentioned anti-cleavage suspension polishing liquid for gallium oxide wafers for fine grinding experiments, and use Unipol-1502 automatic precision grinding and polishing machine to carry out fine grinding processing for gallium oxide wafers. The overall size of the wafer is 15×15mm, and the grinding pressure is 300g/cm ² , the rotational speed of the grinding disc is 80RPM, and the flow rate of the grinding liquid is 20ml/min. After the fine grinding process, the surface of the gallium oxide wafer is complete, and there is no obvious scratch under the light observation. The surface roughness Ra value in the 5×5μm plane area is detected by VK-X100/X200 shape measurement laser microscope. The value is 140nm, and the Sartorisu CP 225D type is used Precision electronic balance (accuracy 0.01mg), weigh the gallium oxide wafer before and after fine grinding, and calculate the grinding material removal rate of the grinding liquid to be 1.1 μm/min. It can be seen that the polishing solution in Example 3 of the present invention is suitable for fine polishing of gallium oxide wafers.

Embodiment 4 The preparation method of gallium oxide wafer anti-cleavage suspension slurry comprises the following steps:

(1) Mix 900g of kerosene and 600g of alkane, and use an electric magnetic stirring device to fully stir and fuse for 15 minutes to obtain the base liquid of the grinding liquid, let it stand, cool to room temperature, and set aside;

(2) Under the condition of stirring with electric magnetic stirring device, add 150g of alumina micropowder of W1.5 type, 50g of hydroxyethyl cellulose, 50g of ethyl cellulose , and 200g of octylphenol polyoxyethylene ether into (1) In the base liquid obtained in the step, fully stir for about 20 minutes, and then use ultrasonic dispersion, the ultrasonic dispersion is 500W, and the dispersion time is 25 minutes, to obtain the intermediate liquid of the grinding liquid, stand still, cool to room temperature, and set aside;

(3) Add 0.4g of polyoxyethylene polyoxypropanolamine ether, 0.4g of benzisothiazolinone, and 1g of isopropyl ketone to the intermediate liquid obtained in step (2), and stir thoroughly for 20 minutes to obtain a quasi-grinding liquid. Place, cool to room temperature, and set aside;

(4) Measure the pH value of the quasi-grinding liquid obtained in (3), and slowly add acid and alkali pH value regulators to the quasi-grinding liquid under stirring conditions as needed, and adjust the pH value of the grinding liquid to weak alkaline , within the required range of 8.0 to 9.0, wherein the acidic pH adjuster is hydrochloric acid, and the alkaline pH adjuster is triethanolamine. After fully stirring and mixing uniformly, the anti-cleavage suspension for rough grinding of gallium oxide wafers is obtained. The grinding liquid is about 2000g.

Take the above-mentioned anti-cleavage suspension polishing liquid for gallium oxide wafers for fine grinding experiments, use Unipol-1502 automatic precision grinding and polishing machine to carry out fine grinding processing for gallium oxide wafers, the overall size of the wafer is 15×15mm, and the grinding pressure is 320g/cm ² , the rotational speed of the grinding disc is 80RPM, and the flow rate of the grinding liquid is 20ml/min. After the fine grinding process, the surface of the gallium oxide wafer is complete, and there is no obvious scratch under the light observation. The value of the surface roughness Ra in the 5×5 μm plane area is measured by VK-X100/X200 shape measurement laser microscope, and the value is 220nm, using Sartorisu CP 225D type Precision electronic balance (accuracy 0.01mg), weigh the gallium oxide wafer before and after fine grinding, and calculate the grinding material removal rate of the grinding liquid to be 1.4 μm/min. It can be seen that the polishing solution in Example 4 of the present invention is also suitable for fine polishing of gallium oxide wafers.

Embodiment 5 comparative experiment:

According to the above method, the grinding liquid in the prior art (mainly composed of W10 boron carbide micropowder and kerosene, which needs to be continuously stirred by a stirring device) was used for rough grinding experiments, and the gallium oxide wafer was roughened using Unipol-1502 automatic precision grinding and polishing machine. For the grinding process, the outer dimension of the wafer is 15×15 mm, the grinding pressure is 500 g/cm ² , the rotational speed of the grinding disc is 50 RPM, and the flow rate of the grinding liquid is 50 ml/min. After the rough grinding process, the surface integrity of the gallium oxide wafer is poor, and penetrating cleavage cracks appear on some wafers. There are many scratches on the surface of the wafer, accompanied by a small amount of pitting, using VK-X100/X200 shape measurement The value of the surface roughness Ra in the 25×25 μm plane area detected by a laser microscope is 4.1 μm. Sartorisu CP 225D precision electronic balance (accuracy 0.01 mg) is used to weigh the gallium oxide wafer before and after rough grinding, and calculate the removal rate of the abrasive material by the grinding liquid. The rate is 3.7 μm/min. It can be seen that under the same conditions, the abrasive liquid in the prior art has poor wafer surface quality effect after rough grinding, and cannot meet the quality requirements of gallium oxide wafer rough grinding.

And the grinding liquid in the prior art ( mainly composed of W0.5 diamond differential and kerosene, which needs to be continuously stirred by a stirring device) was used for fine grinding experiments, and the Unipol-1502 automatic precision grinding and polishing machine was used for fine grinding processing of gallium oxide wafers , the overall size of the wafer is 15×15mm, the grinding pressure is 380g/cm ² , the rotational speed of the grinding disc is 70RPM, and the flow rate of the grinding liquid is 35ml/min. After the finishing process, the surface integrity of the gallium oxide wafer is average, and there are obvious scratches on the surface when observed under the light. The surface roughness Ra value in the 5×5 μm plane area measured by VK-X100/X200 shape measurement laser microscope is 180nm. Sartorisu CP 225D precision electronic balance (accuracy 0.01 mg), weighed the gallium oxide wafer before and after fine grinding, and calculated the grinding material removal rate of the grinding liquid to be 0.9 μm/min. It can be seen that, under the same conditions, the fine grinding material removal rate and wafer surface quality of the suspension grinding liquid involved in the present invention are better than those of the prior art, and are more suitable for fine grinding processing of gallium oxide wafers.

Embodiment 6 stability test

Take the gallium oxide wafer anti-cleavage suspension grinding liquid prepared in the above examples 1 to 4, and store it for 12 months. It is detected that its dispersion uniformity is excellent and the suspension characteristics are stable, which shows that the gallium oxide wafer anti-cleavage suspension grinding liquid provided by the present invention Liquid performance is stable, storage and transportation are convenient.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a gallium oxide wafer anti-cleavage suspension lapping liquid, is characterized in that: it is made up of the raw material of following weight percents:

Alumina powder 1 ~ 10%, dispersion thixotropic agent 1 ~ 5%, tensio-active agent 1 ~ 10%, kerosene 40 ~ 50%, alkane 20 ~ 30%, pH value regulator 1 ~ 3%, foam killer 0.01 ~ 0.03%, sterilant 0.01 ~ 0.02%, helps clean-out system 0.01 ~ 0.1%.

2. gallium oxide wafer according to claim 1 anti-cleavage suspension lapping liquid, is characterized in that: it is made up of the raw material of following weight percents:

Alumina powder 5 ~ 10%, dispersion thixotropic agent 3 ~ 5%, tensio-active agent 5 ~ 10%, kerosene 45 ~ 50%, alkane 25 ~ 30%, pH value regulator 1 ~ 3%, foam killer 0.02%, sterilant 0.02%, helps clean-out system 0.05%.

3. gallium oxide wafer according to claim 1 and 2 anti-cleavage suspension lapping liquid, is characterized in that: described alumina powder is α-Al ₂o ₃, grain size of micropowder is 0.5 ~ 15 μm.

4. gallium oxide wafer according to claim 3 anti-cleavage suspension lapping liquid, it is characterized in that: described dispersion thixotropic agent is one or more mixtures in polyvinyl alcohol and derivatived cellulose, and wherein derivatived cellulose is mainly Natvosol, cyanoethyl cellulose and ethyl cellulose.

5. gallium oxide wafer according to claim 4 anti-cleavage suspension lapping liquid, is characterized in that: described tensio-active agent is one or more mixtures in polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, fatty alcohol-polyoxyethylene ether, aliphatic acid polyethenoxy ether, polyoxyethylene sorbitan monooleate and methyl stearate Soxylat A 25-7.

6. gallium oxide wafer according to claim 5 anti-cleavage suspension lapping liquid, is characterized in that: the mixture that described kerosene is made up of alkane, aromatic hydrocarbons, cyclic hydrocarbon and unsaturated hydrocarbons, and described alkane is the straight chain liquid alkane containing 11 ~ 13 carbon atoms.

7. gallium oxide wafer according to claim 6 anti-cleavage suspension lapping liquid, is characterized in that: described pH value regulator is divided into alkalescence and acid two kinds, and wherein alkaline conditioner is organic bases pH value regulator; Wherein acid regulator is one or both mixtures in hydrochloric acid or phosphoric acid.

8. gallium oxide wafer according to claim 7 anti-cleavage suspension lapping liquid, is characterized in that: described foam killer is any one in polydimethylsiloxane, polyoxyethylene polyoxypropylene tetramethylolmethane ether and polyoxyethylene polyoxy propyl alcohol amidogen ether; Described sterilant is any one in different thiophene quinoline ketone and BIT; The described clean-out system that helps is isopropyl acetone.

9. the preparation method of gallium oxide wafer according to claim 1 anti-cleavage suspension lapping liquid, is characterized in that, comprise the following steps:

(1) by weight percent according to claim 1, kerosene and alkane are mixed, fully stir fused, obtain lapping liquid base fluid, leave standstill, be cooled to room temperature, for subsequent use;

(2) under the condition stirred, by weight percent according to claim 1, alumina powder, dispersion thixotropic agent and tensio-active agent are joined in the base fluid of step (1) gained, stir, re-use ultrasonic disperse, obtain lapping liquid intermediate liquid, leave standstill, be cooled to room temperature, for subsequent use;

(3) help clean-out system to join in the intermediate liquid of step (2) gained in defoamer, sterilant river by weight percent according to claim 1, fully stir, obtain accurate lapping liquid, leave standstill, be cooled to room temperature, for subsequent use;

(4) pH value of the middle accurate lapping liquid of gained of measuring process (3), add acidity or the alkaline pH adjuster of appropriate weight quota as required, slowly be added drop-wise in accurate lapping liquid under the condition stirred, regulate in the scope of pH value to 8.0 ~ 9.0 of lapping liquid, after being fully uniformly mixed, obtain gallium oxide wafer anti-cleavage suspension lapping liquid.

10. the preparation method of gallium oxide wafer according to claim 9 anti-cleavage suspension lapping liquid, described alumina powder is α-Al ₂o ₃, grain size of micropowder is 0.5 ~ 15 μm;

Dispersion thixotropic agent is one or more mixtures in polyvinyl alcohol and derivatived cellulose, and wherein derivatived cellulose is mainly Natvosol, cyanoethyl cellulose and ethyl cellulose.